fix --version and --help
fix --version and --help

Reviewed By: ot

Differential Revision: D2833437

fb-gh-sync-id: 17f7cb1a433f177e741dcf34e7231eadf2025394

ldemailly/wdt,luluandleilei/wdt,luluandleilei/wdt,luluandleilei/wdt,ldemailly/wdt,luluandleilei/wdt,ldemailly/wdt,ldemailly/wdt